The major long range objectives are to advance our knowledge of hormonal, metabolic and genetic factors which inflence growth or maturation in the human fetus, infant, child, and adolescent. These include: 1) Hormonal changes accompanying puberty and their correlation with sexual and somatic maturation, studies on the control of the onset of puberty, negative and positive sex steroid feedback, indirect assessment of LRF secretion, and the pathogenesis and management of disorders associated with delayed or precocious puberty. 2) The use of median eminence studies of synaptosomes, a) as in vitro model for factors affecting release of LRF, somatostatin, and TRF by central nerve terminals; b) for localization by immunoelectronmicroscopy of LRF and somatostatin in synaptic vesicles; c) for studies on ontogenesis of peptidergic synaptosomes. 3) Ontogenesis of CNS regulation of pituitary function, including GH, PRL and FSH, LH and their subunits in the ovine fetus; studies on molecular heterogeneity of fetal GH and PRL, the role of central neurotransmitters and changes in pituitary sensitivity of LRF, synthesis of somatostatin by fetal pancreas. 4) The role of conformation immuno-, radioreceptor and bioactivity of hGH and hCS and the biologic activity of modified and semisynthetic growth hormone preparations in men. 5) Factors which regulate GH secretion: a) role of central neurotransmitters on GH secretion in the dog; b) nosology and pathogenesis of GH deficiency in man, and c) factors affecting response to hGH treatment. 6) Investigation of the control of prolactin secretion in the dog. 7) Further elucidation of the etiology, pathogenesis, and classification of anomalies of sex in man, including a) relation of H-Y antigen to the normal and abnormal gonadal differentiation; b) studies in male pseudohermaphrodism; c) prenatal diagnosis of congenital adrenal hyperplasia (CAH); d) effects of treatment of CAH on growth and reproductive function, e) correlation of sex chromosome constitution and phenotype in syndrome of gonadal dysgenesis and its variants.